Heat-radiating pin.



.No} 827,732. PATENTED AUG. 7, 1906. H.A.KNOX.

HEAT RADIATING PIN.

APPLICATION FILED DBO.30,1904.

UNITED STATES,

PATENT OFFICE.

HEAT-RADIATING PIN.

Specification of Letters Patent.

Patented Aug. 7, 1906.

Application filed December 30, 1904:. Serial No. 239,002-

To all whom it may concern:

Be it known that I, HARRY AUSTIN KNOX, a citizen of the United States of America, residing at Springfield, in the county of Hampden and State of Massachusetts, have invented new and useful Improvements in Heat- Radiating Pins, of which the following is a specification.

This invention relates to heat-radiating devices for heated metal bodies or vessels, and it has special reference to means for dissipating the high temperature generated in the cylinders of internal-combustion engines,

' the object of the invention being to provide a heat-radiating device applied tothe external surface of a cylinder to be cooled; and the essential feature of the invention resides in the construction of the device whereby a relatively large radiating area may be attained at a relatively low cost, while insuring an intimate contact of the radiating device with the cylinder and while also insuring an area of contact with that device sufficiently extensive to permit the rapid diffusion of the heat from said point of contact to the radiating-surfaces; and having these ends in view the invention consists in the construction described in the following specification and clearly summarized in the claims appended thereto.

The invention is fully illustrated in the accompanying drawings, in which Figure 1 is a perspective view of a radiating-pin constructed according to this invention and shown applied in operative position in a portion of a cylinder. Fig. 2 is an elevation of one side of the pin in position in the wall of a cylinder. Fig. 3 is a side elevation of the pin, taken at right angles to Fig. 2, showing in dotted lines the final position of the two parts of the pin. Fig. 4is a crosssection of the pin on line 4 4, Fig. 3. Fig. 5 is a perspective view of a pin in operative position in the cylinder-Wall, a portion of the latter being shown, this view showing a slight modification of the construction shown in Fig. 1. Fig. 6 is a side elevation of thepin illustrated in Fig. 5 before the constituent parts of the pin have been spread apart. Fig. 7 is a cross-sectional view of the pin shown in Fig. 6, the plane of the section being on line 7 7 of that figure. Fig. 8 is a perspective view of a pin embodying a modification of the construction shown in Fig. 1. Fig. 9 is a transverse section of the pin shown inFig. 8, the plane of the section being on line 9 9 of that figure. Fig. 10 shows a part of a pin slightly modified in form, but not difierent i therwise from one of the parts shown in To insure the successful radiation of heat by means of externally-applied heat-radiating devices, two characteristics are essential, viz: first, intimate contact of the device with the heated body, and, second, the observance of proper proportions between the radiating area which extends beyond the surface of the. heated body relative to the area of contact of the device with said body. Furthermore, from a commercial point of view, and hardly less essential, the radiating device should be provided with smooth surfaces to prevent the adhesion of mud thereto when used (as these devices generally are) to cool the cylinders of motors embodied in the construction of automobile vehicles, and to this should be added cheapness of construction and as extensive an area of radiatingsurface as is warranted by the area of the contact-surface between the base of the radiating device and the heated body to which it is applied.

This invention embodies to a high degree all the above characteristics, its distinguishing feature being the combination of longitudinally-disposed metal pieces which may be grouped together to constitute practically a round bar which, by means of a suitable tool for holding the elements of the bar together, may be screwed as a solid bar into suitablytapped-out holes formed in the wall of the cylinder, these holes preferably being drilled into the surface radially. This grouping to gether of these longitudinally-disposed parts permits them to be screwed into a threaded hole as solidly as a round bar may be screwed in, thereby providing the intimate contact between the radiating device and the body of the cylinder above referred to, and the parts may then be separated one from the other, radiating like branches, as it were, from a common base, thus providing a largely-increased area of radiation. Furthermore, the screwthreads located at the base of each of the longitudinally-disposed parts of the radiating device maybe formed in each piece bymeans of a press, thereby greatly reducing the expense as compared with the operation of running a screw-cutting die over a round bar, and yet this work may be done so accurately that when these parts are assembled together in a suitable tool to be screwed into a threaded IIO hole they will constitute a cylindrical bar with an accurately-threaded base.

Referring now to the drawings, a may indicate a portion of a cylinder of an internalcombustion engine having a hole 6 drilled therein and screw-threaded, the radiating device being in the form of a pin composed of two bars 0 and d, half round in cross-section,

as shown in Figs. 1 to 4, which when put together constitute a cylindrical bar, that end of each of said members 0 and d which is to be screwed into the hole I) having screwthreads e and f preferably formed therein by pressure. This produces a perfectly good thread and is far cheaper than. clamping the two bars 0 and d together and then running a screw-cutting die over the ends thereof, although this latter method may be resorted to, if desired, or the radiating-pin may be made up of three elementsg, h, and i-as shown in Figs. 5, 6, and 7, whereby the radiating-surface may be still further increased;

but there would not be any particular advantage in a subdivision of the pin into a greater number of parts than that illustrated in Fig. 5, for the reason that a suitable proportion between the radiating area and the area of contact of the base of the pin and the cylinder could not then be maintained, as it is self-evident that it would be useless to provide a radiating-surface greater than would be necessary to dissipate the maximum degree of heat that could be imparted to said surface from a given area of contact. Of course a greater subdivision of the pin would be feasible if its length were reduced, so that a suitable proportion of radiating-surface to contact-surface could be maintained but ex:

perience shows that a certain height of pin above the surface of the cylinder is desirable to take advantage of the air-currents to which the radiating-pins are subjected. For these reasons it is held that a longitudinal subdivihaving all of the characteristics of that shown 'in Fig. 1, is a 'much more expensive construction and possesses no advantage over I the other to compensate for the additional cost, though it would clearly fall within the sco e of the present invention.

nother modification which would fall within the scope of the invention is shown in Fig. 10, in which is illustrated one of the metal parts of a pin which permits the use of round wire instead of wire rolled to certain cross-sectional form, as illustrated by the sectional views, Figs. 4 and 7.

In using the round wire the end thereof, when put under a press to stamp the screwthreads therein in the manner described, also effects the offsetting of the base of the pin relative to the body, as at m, and strikes up said end, either in half-round form, as shown in Fig. 4, or in triangular form, as shown in Fig. 7, to permit the assemblage of the parts by twos or by threes, whereby these ofiset threaded ends of the pin when properly assembled Will constitute a substantially cylindrical bar which may be screwed into a threaded hole as one piece in the manner described relative to the constructions shown in Fig. 1 or in Fig. 5. But by forming the offset ends on the pin, as shown in Fig. 10, it permits the use of the round wire, as stated, which is one advantage, and also effects the separation of the constituent longitudinally-disposed parts of the pin in separated and substantially parallel relations, thereby giving freer access of the air to all of the radiating-surfaces.

While from a practical point of view the securing of the radiating devices herein described by screwing the same into suitablythreaded holes in the cylinder is the only method which will insure their rigid attachment in operative position, it is conceivable that they might be attached to the cylinder in some other wayas, for example, after assemblage they might be brazed in the holes; but, however they may be secured therein, the finished structure would obviously fall within the scope of this invention, which consists, essentially, of a radiating device having separate branches extending radially from a common base, the latter being adapted to enter and be secured in a hole in the cylinder in intimate contact with the latter.

In the preferred embodiment of the invention the separate divergently-related units of the pin are of half-round form in cross-section i. e. provided with smooth rounded outer surfaces and smooth flattened inner faces, which add materially to the radiatingsurface of the pin. Furthermore, in this construction a distinctive advantage arises from the fact that the flattened inner faces of the pin units provide a large area of exposed radiating-surface between the units and also insure a free air circulation therebetween. Another practical advantage of the construction is that the entire radiating-surface of the pin on both the rounded and flattened faces thereof is entirely without ribs or corrugations of any character. This is impor tant for the reason that it has been found in practice that a. corrugated or ribbed pin holds the mud which splashes on it in wet Weather, and the heat of the pin bakes the mud so hard that it is diflicult to remove it, thereby putting the engine out of action un til the pins have been cleaned. By employing a smooth pin of the construction referred to mud can easily be removed with a stream of Water. Also an important advantage, from a manufacturing and commercial standpoint, resides in the fact that by making the pins of two bars, as described, it is possible to manufacture the same by simply cutting the pin units 0H from a piece of metal and stamping the screw-threads there in by a suitable die.

Having thus described my invention, What I claim, and desire to secure by Letters Patent of the United States, is

1. A heat-radiating pin for the cylinders of internal-combustion engines and the like comprising a plurality of rod members spaced apart for the greater portion of their length and provided with smooth outer surfaces, said rod members meeting at one end to form a cylindrical base-stud for tight engagement in a single hole in the engine-cylinder.

2. A heat-radiating pin for the cylinders of internal-combustion engines and the like comprising a plurality of divergently-related rod members provided with separate smooth outer rounded and inner flattened, radiating surfaces, said rod members meeting at one end to form a cylindrical base-stud for tight engagement in a single hole of the enginecylinder.

3. A heat-radiating pin for the cylinders of internal-combustion engines comprising a plurality of separated units, each consisting of a rod-section with a smooth rounded outer surface and provided at one end with a section of threads, the separate threaded ends of said units matching in registering relation to form a cylindrical divided base-section screwed into a single hole in the enginecylinder.

HARRY AUSTIN KNOX.

Witnesses:

WM. H. OHAPIN, K. I. CLEMoNs. 

